TWO TRYPETIDAE FROM THE MARQUESAS ISLANDS, WITH
ONE NEW SPECIES (DIPTERA)*
By
JOHN
R.
BUREAU of
SURVf;Y,
OF BIOLOGICAL SURVEY,
MAI,LOCH
MALLOCH
U. S. DEPARTM£NT
Df;PARTMF,NT OF AGRICULTURE
AGRICULTURf;
INTRODUCTION
The genus Dacus Fabricius is one of the most important economically in
the Pacific islands, and there are many species that feed in their larval stages
in cultivated fruits, causing considerable loss to growers. The genus, in the
strict sense as I accept it, is found in Africa, but the subgenus Chaetodacus
Bezzi is met with throughout the Orient and southward into Australia.
Unfortunately many of the species are quite imperfectly understood and
considerable doubt exists on the score of distinguishing characters. However, there can be no doubt of the specific distinctness of the species recorded
and redescribed below, as it is abundantly differentiated from any allied
form in both color and in structure.
I have published a specific synopsis of the genus as far as the species
but· did not include the present one. It will be
are now known to me 39 but
easy, however, to run it out by means of the characters employed in that
paper and it is the only species of the genus which I have seen from the
Marquesas. The description below is offered to supplement the original one
in which there are unfortunately several omissions of important characters,
and I feel that a new subgenus is necessary for its reception.
Genus DACUS Fabricius
Subgenus MARQUESADACUS. new subgenus
This subgenus is distinguished from the others already known by the
presence of but one pair of incurved orbitals and their distance from the
recurved pair.
Dacus (Marquesadacus) perfuscus Aubertin.
Chaetodacus perfuscus Aubertin: Entomologist, vol. 62, p. 173, 1929.
Male and Female
Length, 6.5 mm. to 7 mm. Head reddish yellow, frons darker, with the very narrow
frontal orbits greyish white dusted, occiput with a large black triangle on each side
above, antennae fuscous, apex of second segment and base of third, especially on inner
on
..
1931,
39 Malloch, J. R,
R., Trypetidae: Insects of Samoa, pt. 6, fasc. 7, pp. 253-266, London, 1931.
'4.
* Pacific Entomological Survey Publication I, article 14.
[ 145]
145 ]
146
Museum--Bulletin 98
Bernice P. Bishop Museu11'Ir-Bulietin
side, reddish yellow; face without black spots, palpi yellow; frontal and vertical bristles
black. Thorax glossy black, the only yellow markings consisting of a round spot on
metapleura and a large triangle on posterior margin of mesopleura, the prosternum
fulvous yellow; abdomen entirely glossy black, even the membrane fuscous. Legs
glossy black, fore coxae and femora entirely honey yellow. Wings hyaline, with a
well developed black stripe on the costa from apex of subcosta to apex of fourth
vein, which does not extend much beyond level of second vein anywhere, and is but
slightly widened apically, the dark color traceable along the second vein almost to
its base; anal streak rather faint, cross veins not clouded. Calypteres grey. Halteres
yellow.
Frons about 2.5 times as long as wide, with but one bristle on each orbit anterior
to the pair of recurved bristles on the upper glossy vittae; all four verticals present;
face without a marked central elevation in profile. Mesonotum with the usual 4 anterior marginal bristles, 2 notopleurals, 2 prescutellars, 2 postalars and 1 supra-alar;
scutellum with 2 bristles, its apex almost transverse, sometimes with a slight elevation
in center between the bristles; mesopleura with one hind marginal bristle, pteropleura
without a distinct bristle, merely haired. Abdomen with the tergites well differentiated,
extensile, and with many setiferous punctures, the fourth visible tergite with the usual
more finely haired depressed patch on each side. Legs normal. Cross veins of wing
separated by about the length of outer one.
Nukuhiva: Teuanui, Tovii [Toovii], altitude 2,000 feet, October 27, 1929,
taken at rest on under side of leaves, 31 specimens, Mumford and Adamson.
Tahuata: Vaitupaahei, altitude 1,75° feet, July 9, 1930, 1 specimen,
LeBronnec and H. Tauraa.
Uapou: Hakahetau Valley, altitude 1,000 to 2,000 feet, January 31, 1930,
10 specimens; altitude 1,000 feet, January 22, 1930, 9 specimens; Papaika,
December 14, 1929, 11 specimens, R. R. Whitten.
Recorded from Hivaoa, Tahuata, and Nukuhiva, January, 1925.40
This species is distinguished from all others of which the descriptions
or specimens are known to me by the entirely glossy black color of the
dorsum of the thorax and abdomen, including the scutellum and humeri, the
color markings of the legs, and the presence of but one pair of frontoorbital incurved bristles, which are situated very far forward, indicating
that it is the upper pair that is lacking.
Unfortunately there are no records of the food habits of the species on
aily of the specimens, which were collected in general field work.
any
Genus TRYPANEA Schrank
This genus is very widely distributed, being found
and regions.
Trypanea simplex, new species (fig. 42).
III
In
all faunal zones
Male and Female
Length, 4 mm. to 5 mm. A testaceous yellow species, with thorax and abdomen
black and covered with dense grey dust which obscures the entire surface, the mesonotum
without dark markings, and the wings as in figure 42.
.. Auberrin, D., and Cheesman, L. E., Diptera of French Oceania: Entomologist, vol.
p. '7.4, '9 2 9.
62,
M arquesan Insects-I.
147
Frons about 1.5 times as long in center as its width at vertex, much narrowed to
anterior margin where it is one-third narrower than at vertex, the orbits each with
5 or 6 bristles; epistome rather sharply produced in center, parafacials linear in profile,
height of face not over two-thirds that of back of head; third antennal segment angular
at upper apical corner; arista bare; proboscis short and stout; palpi normal; eye
obliquely placed; gena not over one-fourth of the eye height. Thorax with the usual
2 pairs of long postsutural dorsocentral bristles; scutellum with 2 strong marginal
bristles, decumbent hairs on thorax and abdomen all white or yellowish white. Legs
normal, fore femora with some rather long bristles on the apical half of the posteroventral surface; fore tarsi of male slightly thickened and with a few rather long
hairs along the posterior side, those of the female slender and without outstanding
posterior hairs. Wings as in figure 44, first vein setulose from proximad of humeral
cross vein to its apex above, and on apical fourth below, third bare above and with
a few widely spaced fine hairs on basal portion below.
'-J,
\.,
~r
"""--~'~
FIGURE 42. Wing of Trypanea simplex, new species.
FICUIU:
Hivaoa: Atuona Valley, altitude 330 feet, February 25, 1929, holotype
female, Mumford and Adamson.
Eiao: coconut plantation, near center, sweeping, October 1, 1929, allotype,
A. M. Adamson.
Uahuka: Putiovai, March 23, 1931, paratype female, LeBronnec and
H. Tauraa.
•